avoiding collision by eye or radar 141
Pass a tug and tow only aft er you sight and identify all lights on each vessel. If
necessary, stop, heave-to, or anchor. Use binoculars to scan the horizon astern for
the vessel being towed. Follow these steps:
Q on the tug (towboat)
Sight and count the white masthead lights.
Make sure you count two or three masthead lights.
Sight the yellow-over-white stern lights. Wait until you are positive you see the
yellow light. Th ese can be quite diffi cult to see from a distance (they look white).
Q on the tow (vessel being towed)
Sight the sidelights. Remember that the sidelights might be at the
forwardmost corners.
Sight the stern light. Look low. Barge stern lights are diffi cult to sight in
a seaway.
Th e lights on a power-driven vessel (PDV)
help defi ne the heading of the vessel. When
a tug is towing astern, the light patterns
defi ne the distance of the towed vessel behind
the tug.Identify Vessels Towing Barges Alongside or Pushing Th em Ahead
Tugs coming in from stern-towing along the coast or over the ocean often
shorten their hawser once they are inside the jetties. For better control, they oft en
lash the tow alongside. In extremely narrow channels such as the Intracoastal
Waterway, tugs push barges ahead. Th is provides better control for turning and
maneuvering through narrow bridges. Below are clues to the light patterns you
will see on these types of vessels.
Tugs Towing Alongside or Pushing Ahead
Masthead lighting. Tugs towing barges alongside (on the hip) or pushing them
ahead always show two white masthead lights in a vertical line. (This is the